Heat release and absorption are always associated with a state change of a substance and thus thermal analysis with calorimeter is applicable to a variety of phenomena including phase transition, such as melting and crystallization, as well as glass transition, heat curing, purity and compatibility and is widely generalized as a method of analysis of organic materials such as polymers and liquid crystals, inorganic materials, such as metal, glass and ceramics, medicals, foods, perfumery, cosmetics or the like. A typical calorimeter employed in thermal analysis is a differential scanning calorimeter (DSC).
The differential scanning calorimeter (DSC) is a device for, while scanning temperature, measuring a difference in heat release and absorption of a sample and a reference substance, and measuring an endothermic and exothermic value due to a state change of a sample. There are two types of DSC, heat flux DSC and power compensation DSC. The heat flux DSC is a method for, while scanning temperature, recording a temperature difference between a sample and a reference substance with respect to time (or temperature). The power compensation DSC is a method for, while scanning temperature, supplying a heat flow to a sample and a reference substance so as to eliminate a temperature difference between a sample and a reference substance, and recording a difference of the supplied heat flow.
FIG. 16 shows a device configuration of a heat flux DSC which is currently widely utilized. This device has a temperature-controlled thermal bath 103, and at a symmetrical position in the thermal bath, a sample X and a reference substance Y are set. Between the thermal bath 103 and the sample X and between the thermal bath 103 and the reference substance Y, thermal resistance bodies 104 are provided, and in predetermined locations of the thermal resistance bodies 104, a temperature difference is detected. Heat release and absorption of the sample X and the reference substance Y is carried out via the thermal resistance bodies 104. A temperature of the thermal bath 103 is managed by a temperature control unit 111, which has received a command from a computer 110, controlling a heater drive unit 112. A difference of a heat flow which is flowing between the thermal bath 103 and the sample X and between the thermal bath 103 and the reference substance Y is in proportion to a temperature difference under detection. This temperature difference is detected by temperature detectors 105 employing temperature-voltage conversion elements (such as thermocouples or thermopiles), the detected difference is output as a thermoelectromotive force difference (DSC signal), and the output difference is input to a temperature recording unit 107 or a temperature difference recording unit 108 via an amplifier 106. The DSC signal is calibrated while a standard substance such as a sapphire of which a heat capacity is known is employed as the sample X, a device constant (V/W) indicative of what V of thermoelectromotive-force difference occurs with respect to a heat flow difference of 1 W is obtained, and the thus obtained constant is converted to a heat flow (W). This device constant is also referred to as calorimetric sensitivity, and in the present specification, it is referred to as calorimetric sensitivity. By time-integrating the DSC signal that is thus converted to the heat flow, the quantity of heat (J) which is released or absorbed is obtained.
A thermal resistance body 104 and a temperature detector 105 are integrated with each other, and are referred to as a heat flux sensor or a heat flow sensor. A heat flux (W/m2=J/s·m2) is the quantity of heat flowing per unit time per unit area, a heat flow (W=J/s) is the quantity of heat flowing per unit time and thus these two elements are different from each other in physical quantities. What is actually measured is a heat flow and thus in the present specification, it is referred to as a heat flow sensor.
Although a general configuration and principles of a differential scanning calorimeter have been described hereinabove, in the field of such differential scanning calorimeter, publicly known techniques shown in Patent Literature 1 and Patent Literature 2 are known as using a semiconductor thermoelectric element or a thermoelectric module (also referred to as Peltier element or thermo-module) as a heat flow sensor instead of a thermoelectric couple so as to thereby have a high sensitivity. Also, as a thermoelectric element, there is a publicly known technique or the like shown in Patent Literature 3.